A thin film transistor display (TFT-LCD) is applicable widely to a variety of fields in production and life. When displaying is performed, the TFT-LCD drives respective pixels in the display panel through a driving circuit to display. The driving circuit of the TFT-LCD comprises mainly a gate driving circuit and a data driving circuit. Herein, the data driving circuit is configured to latch sequentially and timely input data according to a clock signal and inputs latched data to a data line of the display panel after converting the latched data into an analogy signal. The gate driving circuit is implemented generally through a shift register, which converts the clock signal into a turn-on/turn-off voltage to be output to respective gate lines of the display panel. One gate line on the display panel is usually connected to one shift register unit (i.e., one stage of a shift register). Progressive scanning of pixels in the display panel is realized by making respective shift register units output a turn-on voltage by turns and in order. Such progressive scanning of pixels can be divided into unidirectional scanning and bilateral scanning according to scanning directions. At present, in mobile products, it usually requires being capable of realizing bilateral scanning by taking into account of an increase of production capacity and yield rate of mobile products.
In other words, as the panel display develops, high resolution and narrow frame have become a trend. Due to such trend, technique of gate driver on array (GOA) emerges. The GOA technique integrates directly the gate driving circuit of the TFT-LCD on an array substrate to take place of a driving chip (IC) which is bonded on an outside edge of the panel and manufactured by a silicon chip. Since such technique can make the driving circuit on the array substrate directly, there is no need to bond IC and wirings around the panel, which reduces manufacturing processes of the panel, reduces cost of products, and at the same time improves integrity of the TFT-LCD panel, so that the panel realizes narrow frame and high resolution. However, the GOA technique has inherent problems such as service life or the like. In GOA design of actual products, how to use fewer circuit elements and devices to realize functions of shift registers and reduce electric stress of major TFTs to maintain the gate driving circuit to operate stably for a long time is a key problem of the GOA design.